There’s a link on the BACB website you can search by zip code, look up original certification date, and email them (if they’ve enabled that feature) here:
https://www.bacb.com/services/o.php?page=101135
I’d start with a BCBA search, look for some with an early original certification date, and just email a few.
Some states also have LBA designations you might search
separately for as well.